Process for obtaining crepe effects on fabrics



Patented Feb. 8, 1938 PROCESS FOR OBTAINING CREPE EFFECTS ON FABRICS Hans Altwegg and Armin Eichler, Freiburg, Germany, assignors, by mesne assignments, to E. ii. du Pont dc'Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application April 6, 1931, Serial 6 Claims.

Crepe effects are generally obtained on materials by the use of highly twisted warp or weft threads; and special effects are obtained by definite alternation of warp or weft-yarns, highlytwisted to left and to right. This process can be applied to artificial silks which, like viscose silks, for example, consist of regenerated cellulose.

Fabrics which contain as their warp or weft highly twisted, viscose yarns show a valuable crepe effect on being treated with warm water, that is, for example, after having been subjected to a process for removing the dressing or to a dyeing process. This results from the fact that highly twisted viscose yarns possess the property, on being treated with water or with aqueous solutions of all kinds, of curling and simultaneously shrinking on drying. If such yarns are present as warp 'or weft in the fabric and if these fabrics are treated in the way indicated, distortion of the fabric takes place resulting in the socalled crepe effect. 7

However, if this method of treatment is applied to fabrics, the warp or weft of which consists of highly twisted threads of acetyl cellulose, the crepe effect either does not occur at all or else only to an extent which is hardly noticeable. "The highly twisted acetate silk threads do not possess, or, in any case, only to a slight extent, the property of curling and shrinking in contact with warm water.

It has now been found that highly twisted threads of acetyl cellulose acquire the property of producing valuable crepe effects in fabrics when treated with waterif they contain substances which have for water a high affinity. Such substances belong to various classes of bodies and include, for example, inorganic salts such as calcium chloride or nitrate, or salts of organic acids such as those of lactic acid.

In order to obtain crepe eifects, acetate silk yarns which contain such substances as have been mentioned above are highly twisted and made to constitute the warp or weft of the fabric. The fabric thus obtained is thereupon subjected to a treatment with an aqueous medium. The treatment can be performed separately or simultaneously with another step in manufacture as for example, with the treatment in the bath for removing the dressing or in the dye bath.

Example Ordinary acetate silk threads of deniers centimetre.

In Germany April Ill, 1930 (Cl. 28l) with 24 individual threads and an arrangement of 51 threads to the centimetre, are used for the warp of a fabric, the weft consisting of acetate silk thread containing 10% sodium lactate, twisted alternately left and right, of the same standard of fineness, having 2800 twists per metre and an arrangement of 30 threads to the After weaving, the material is treatedin a bath with pure water at C. In this way a beautiful crepe effect similar to crepede-chine is obtained.

What we claim and desire to secure by Letters Patent is: r

1. A process for producing crepe effects on fabrics which comprises fabricating highly twisted cellulose acetate yarns containing a calcium salt which is very soluble in water into a fabric, and treating the fabric with an aqueous medium.

2. A process for producing crepe effects on fabrics which comprises fabricating highly twisted cellulose acetate yarns containing calcium chloride into a fabric, and treating the fabric with an aqueous medium.

3. A process for producing crepe effects on fabrics which comprises fabricating highly twisted cellulose acetate yarns containing calcium nitrate into a fabric, and treating the fabric with an aqueous medium.

4. A process for producing crepe effects on fabrics which comprises fabricating highly twisted cellulose acetateyarns containing a calcium salt which is very soluble in water into a fabric; and treating the fabric with an aqueous medium simultaneously with another step in the manufacture of the material.

5. A process for producing crepe effects on fabrics which comprises fabricating highly twisted cellulose acetate yarns containing calcium chloride into a fabric, and treating the fabric with an aqueous medium simultaneously with another step in the manufacture of the material.

6. A process for producing crepe effects on fabrics which comprises fabricating highly twist- 4 HANS AL'I'WEGG. ARMIN EICHLER. 

